[hp50g]

Yep. I saw this with my own eyes once. I had a disreputable youth in the 1980s which involved trying to steal linesman sets (for phreaking) from those old yellow BT Bedford vans (anyone remember Busby?)

One of them turned out to be a spook wagon. This was in Islington in north London. Really nearly got in deep shit on that one.

People might think you are nuts but its spot on and its worse now than ever.